A piece of iron was heated to 95.4oC and dropped into a constant-pressure calorimeter containing 284 g of water at 32.2oC. The final temperature of the water and iron was 51.9oC. Assuming that the calorimeter itself absorbs a negligible amount of heat, what was the mass (in grams) of the piece of iron? The specific heat of iron is 0.449 J/(g•oC), and the specific heat of water is 4.18 J/(g•oC).